I feel like this book is the real beginning of the world known as Shannara. The Legends of Shannara series starts after "our" world has ended and a small enclave of various races and creatures have taken shelter within a magical foggy shield. The world has been kept at bay as it crumbles under countless disasters, but this small group has lived in peace behind their magical walls, forming the beginnings of the kingdoms and regions I've grown to love over the vast Shannara series.
But the walls begin to crumble, and the outside world comes calling in a rather vicious and bloodthirsty way. Having been protected for so long, the people of Shannara are not prepared and don't even really believe the scouts who spotted the intruders - and the invaders. The outside world has been struggling to survive, and the formerly sheltered valley looks like a place they want to call home as well.
I found a lot of those traditional fantasy elements that I love so much. A handful of people slowly becoming a small part of 5 or 6. Different races and regions coming together, trying to save a world that doesn't even know (or want to admit) that it needs saving. Enemies and dangers hiding in plain sight and betrayal always a possibility with each new turn. By the end of the book, the lines have been drawn and many of the sides have been determined, but I haven't even gotten to the big fight yet. Things are still being prepared, and you never know what could happen next.